1. Field of the Invention
This invention concerns the field of reaction injection molded elastomers.
2. Related Art in the Field
Our U.S. Pat. Nos. 4,254,069 and 4,272,618 concern the curing of RIM polyurethane elastomers. In the glossary of these patents, a "polyol" is defined as a di- or greater functionality high molecular weight alcohol or an amine terminated molecule composed of ether groups. In the discussion of chain extenders in these patents, amines, including aromatic diamines, are disclosed. However, the actual examples are of polyether polyurethanes using polyols (hydroxyl terminated) of high molecular weight. The chain extender, monoethanolamine, was used as a crosslinker.
U.S. Pat. Nos. 4,396,729; 4,444,910 4,333,067 concern elastomers prepared using a high molecular weight amine terminated polyether, an aromatic diamine chain extender and an aromatic polyisocyanate which may merely be a polyisocyanate or a quasi-prepolymer prepared from a polyol reacted with a polyisocyanate wherein some isocyanate groups are still left unreacted. These patents and other related patents state that certain aliphatic amine chain extender materials as disclosed in U.S. Pat. Nos. 4,246,363 and 4,269,945 (see below) may also be used. Various patents have been applied for and received using the basic combination recited above as well as various mold release agents and other additives, for example, catalysts.
European Patent Application No. 81,701A concerns reaction injection molded elastomers. The corresponding U.S. application Ser. No. 443,444, filed 11/22/82, is the subject of interference proceedings with the '729, '910 and '067 patents referred to above (Interference Nos. 101,393; 101,394; and 101,395).
U.S. Pat. No. 3,838,076 discloses foams made from amine terminated polyethers, wherein the amine termination ranges from 10 to 50 percent.
Quillery's U.S. Pat. No. 3,523,918 describes the use of amine chain extenders for the preparation of integral skin foams. Also, Bayer's U.S. Pat. No. 4,218,543 describes the use of high molecular weight polyols, certain aromatic diamines and isocyanates for the production of RIM parts. This Bayer patent specifically claims as a chain extender 1-methyl-3,5-diethyl-2,4-diaminobenzene (diethyltoluenediamine) and its isomer.
U.S. Pat. No. 4,523,004 discloses the substituted aromatic diamine chain extenders of this application in a RIM product.
Turner's U. S. Patent No. 4,246,363 claims a RIM polyurethane composition derived from using at least three different polyols (some are actually amine crosslinkers, both aliphatic and aromatic having specific relationships and reactivity and solubility parameters to one another. Also, Vanderhider's U.S. Pat. No. 4,269,945 claims a process for preparing RIM polyurethanes wherein a relatively high molecular weight hydroxyl containing polyol, a chain extender and a polyisocyanate are used. The chain extender may be an aliphatic amine containing material having at least one primary amine group.
U.S. Pat. No. 4,530,941 discloses reaction molded polyurethanes prepared from a composition comprising (a) a relatively high molecular weight polyol, (b) a chain extender, and (c) a polyisocyanate or polyisothiocyanate improved by replacing a portion of the relatively high molecular weight polyol with an aminated or partially aminated polyoxyalkylene material.
U.S. Pat. No. 4,578,446 discloses the use of an alkyl substituted chain extender wherein the chain extender is used in a polyurethane cast elastomer process.
U.S. Pat. No. 4,631,298 discloses blending various slower reacting chain extenders with diethyltoluene diamine in a RIM system using amine terminated polyethers. Co-pending application Ser. No. 06-926,151 filed 11/3/86 discloses the use of substituted aromatic diamine chain extenders with unsubstituted aromatic diamine chain extenders such as diethyltoluene diamine (DETDA) to slow the reaction rate. The reference to amine chain extenders disclosed in U.S. Pat. Nos. 4,246,363 and 4,269,945 is included also.
Numerous other patents or patent applications disclose and/or claim RIM plastics made with the ingredients of U.S. Pat. No. 4,433,067 plus other ingredients. For example, U.S. Pat. No. 4,474,901, columns 2 and 3, disclose the use of certain low molecular weight aliphatic primary amines. Aliphatics are disclosed in various U.S. Pat. Nos., including 4,585,850 and 4,607,090 as crosslinkers.